The world of polymers has progressed rapidly to transform material science from wood and metals of the 19th Century to the use of thermoset polymers of the mid-20th Century to the use of thermoplastic polymers of later 20th Century.
Thermoplastic elastomers combine the benefits of elastomeric properties of thermoset polymers, such as vulcanized rubber, with the processing properties of thermoplastic polymers.
Medical tubing is made from a variety of materials, typically sterilized and diameters are small. Glass, metal, plastic, and silicone rubber tubing are used in a variety of medical applications. The material commonly used for medical tubing is plasticized polyvinyl chloride (PVC). The plasticized PVC, however, is considered to be undesirable not only because of the migration of the plasticizer to the surface but also because of halogen-containing compounds are not favored. It is therefore generally of great interest to develop an alternative non-halogen material for the medical tubing to replace the plasticized PVC.
For example, one manufacturer of elastomeric material, Kraton Polymers U.S. LLC, has brought two hydrogenated styrene-butadiene copolymers (SBC) to the market, which have been identified as useful for medical applications, namely: grades MD6932 and MD6945. Kraton Polymers U.S. LLC has also filed a patent application, WO 2005/095511 A1 (Maris et al.), which identifies hydrogenated styrenic block copolymer compositions which are useful for overmolding in medical tubing applications.